Protective Effects of Herbal, Woody and Lianoid Plant Polysaccharides Against Diabetic Nephropathy: A Review

Diabetic nephropathy (DN) is one of the most severe microvascular complications of diabetes mellitus and has become the leading cause of end-stage renal disease. Natural plant polysaccharides are bioactive natural macromolecular compounds widely distributed in medicinal plants, fruits, vegetables and cereals. Owing to their multi-target effects and low toxicity, they have attracted considerable attention in the prevention and treatment of DN. Numerous studies have shown that plant polysaccharides may exert renal protective effects through various mechanisms, including antioxidative stress, anti-inflammation, anti-fibrosis, podocyte protection, inhibition of advanced glycation end-product formation, and regulation of the gut microbiota. This paper systematically reviews recent research advances concerning plant polysaccharides for DN intervention, with an emphasis on their action mechanisms, and discusses the structure–activity relationships. However, there are still challenges facing the clinical translation of polysaccharides, including low bioavailability and difficulties in quality control. Future research should focus on the precise analysis of the advanced structure of polysaccharides, clarification of the mechanism of action based on the intestinal microecology, and the development of new delivery systems to promote the clinical application of plant polysaccharides in DN treatment.